Snowdrift

This module computes the preferential deposition and redistribution of snow by the wind (see Snowdrift). It is enabled using the "--enable-drift" command line option.

Warning

Please note that this module is considered highly experimental! It is computationally inefficient and not parallelized.

Most of the module's configuration is done through constants defined in the first few lines of snowdrift/SnowDrift.h. Otherwise, it is necessary to define a spatial interpolation algorithm for the air temperature TA (in MeteoIO) and it is recommended to rely on either CST or AVG or AVG_LAPSE for best results.

It is also necessary to provide pre-computed 3D wind fields for each timestep. They must be based on the same DEM as the whole Alpine3D simulation and be in the ARPS ascii format (see MeteoIO's documentation for the format and configuration options). These wind fields are attributed to each timestep with the WINDFIELDS configuration key in the [Input] section of the ini file. It contains a space delimited list of wind fields files (within GRID3DPATH) and associated number of time steps:

[Input]
GRID3D      = ARPS
GRID3DPATH  = ../input/wind_fields/
 
WINDFIELDS  = sw3.asc 1 nw3.asc 3 ww0.asc 2 nw9.asc 5 nw6.asc 10 ww0.asc 5 sw3.asc 6 nw3.asc 1

In the given example, the wind field file "sw3.asc" will be used for the first timesteps of the simulation, then the wind field file "nw3.asc" will be used for the next 3 timesteps, etc As shown in this example, it makes sense to pay attention to the naming of the wind fields files for clarity (the extension could be omitted as it is automatically appended to the provided file name. By default, it is ".asc" but this can also be configured in the ARPS plugin).